Combined rim stretcher and frame bender



Oct. 20, 1925- E. .1. OVINGTON COKBINBD RIM STRETCHER AND FRAME BENDER Filed Aug. 8, 1923 INVENTOR,

\N7ITNESSES,

Patented Get. 20, 1.925.

UNITED STATES 1,557,6fi? PATENT OFFICE.

EDWARD J. OVINGTQN, OF A UBURNDALE, MASSACHIISETTS, ASSIGNOR, BY MESNE AS- SIGNMENTS, TOJOSEPH W. CROWELL, OF NEWTON CENTER, MASSACHUSETTS.

' COMBINED RIM STRETCHER AND FRAME BENDER.

Application filed August 8, 1923. Serial No. 656,362.

T call whom it may concern:

Be it known that I, EDWARD J. OVINGTON, a citizen of theUnited States, residing at Auburndale, county. of Middlesex, Commonwealth of Massachusetts, have invented certaiinf new and useful Improvements in Combined; Rim Stretchers and Frame Benders, of which the following is a specification. Q .:This; invention relates toa combined rim stretcher? andeframe bender for stretching, bending and :shaping the rims, nose bridge, temples i-and. other parts .of. spectacles, eye glasses, etc. Eo1' the purposes vof this .application-I shall discuss my invention 'inits relation'to the familiar spectacles or eyeglass frames of zylonite, although it will be understoodthat such treatment ;-is purely illustrative and in no way-limiting. The various artsof the zylonite frame may be stretche ,bent, and shaped by heating the zylonite sufliciently to soften it.

,Various-forms of heaters have-beende vised for this purpose of which the most.

satisfactory has been an internally heated frusto-conical shell over which the rims are adapted to be slipped and progressively movedtherealong until stretched to the desired degree. In such prior devices, however,-so ar as I am aware, no provision has been made-for uniformly distributing the heat, with the result that the temperature of the shell varies at different points throughout its extent. Such variations in temperature makes for uncertainty in stretching the rims. Moreover, in such prior devices no suitable means have been provided for a combination of the above feature with a rising column of heated air, over which the zylonite frame may be held toipermit bending, shaping and forming the different parts of the frame, more especially the nose bridge and temples.

To the end therefore, of providing a heater of the class indicated in which a rising column of hot air will be produced and in which the heat will be distributed uniformly throughout the extent of thedescribed, although I do not wish to limit myself to this. means. IV here an electric heater is used, I secure a considerably increased resistance in a. relatively short winding bylthe use of a special resistance unit. -.The construction and manner of assembling and using my heater, togetherwith selected embodiments thereof which swell illustrates the principles involved, are described and shown in the accompanying specification. and drawings, and the charac teristic features of-novelty are particularlypointed out ,in' the appended claims. Throughout the specification and drawings like reference characters are correspondingly applied. In the drawings:

Fig. 1 is an elevation, partly in section, of an electric heater in accordance with my invention.

Fig. 2 is a plan section on the line-2-2 of Fig. 1. I

Fig. 3 is a view similar to Fig. 1 and showing a: modification to be used with separate, detached heating means, and

Fig. 4 is an enlarged detail view of the resistance. unit shown in Fig. l.

Referring toFigs. 1 and 2, I have indicated at l a footed base and at 2 a frustroconical shell seated within and detachably clamped at 3 within said base. The shell may be graduated exteriorly as indicated in Fig. l and the upper end thereof is preferably perforated as indicated at 4, Fig. 1. Set within the base 1 is a bridge piece 5 of suitable insulating material, to which the terminals 6 of the lead wires 7 are connected. Mounted upon the bridge piece 5 is the resistance unit which, as here shown, consists of an insulating plate 8 of mica or the like across which the resistance wire 9-is threaded from end to end thereof. The plate 8 tapers upwardly from bottom to top in approximate conforn'iation with the taper of the shell 2, and at its opposite edges is provided with converging rows of holes 10 through which the resistance wire is threaded in a series of spaced superposed turns of gradually decreasing diameter from tion and distribution of the heat. After the series 'of turns has been made in the wire, the free end of the wire is brought down one edge of the ,plate through a series of holes 11',- see Fig. l, both ends of the wire then being connected to the terminals 6 of the lead wires 7.

As shown herein, the resistance winding is a coiled wire. Such a Winding possesses considerably greater resistance per unit of length, as compared with the ordinary straight unco'iied wind 'mg. In practice, the relation is approximately 7 to l, that is to say, one lineal inch of coiled wind-ing is the equivalent in length and therefore in resistance 'of approximately seye n inches of straight unveiled wire. This lllcfiiiis ed res'is'taince in a relatively short windin is very important- Where high resistance windings have to be 'nade in a s'inall-sp'ace. Moreover, the coiled winding possess s advanta es over the straight viiin'ding injiespedttothe matter of assembling the winding-upon the insulating plate.

With any wihdin-g, each turn is put under tension when it is threaded through the staggered holes 'ofth'e insulating plate. This insures that the winding will'dlose'ly hug the insulating plate and that the turns thereof will be separated from each other at the holes in the plate. 'After assembling, the terminal ends of the "cdi'led wire may be stretched to any re uired length for connection with the terminals 6' of the lead wires '7 without displacing the ie'st of t-he winding.

This avoids the necessity of exercising e3:- treine care in threadim the wire through the holes to make suretl iatthe ends thereof are the proper le gth, as is'ne'cessar with a straight, unc'oil'ed wire which Cannot be sfire'teh'cd.

In using this form o f my h'eat'er, the frames of xylem-ire o1- oth'er material are sl'ipp'e'd onto the artistic-conical shell from above and are moved downwardl until stretched to the desired degree. The radiant he'at from the resistance unit is distributed uniformly throughout the length of the shell. The air contained within the shell is also heated and, rising, causes the shell to be heated more quickly and more uniformly tha n if the heat were applied in some other way, as for example, to an ainper forated shell. Moreover the perforations 4 at the top of the shell make this rising column of heated air available for bending and shapin g the nose bridge, temples and other parts of the spectacles or eyeglasses heldover said perforations.

In the form of my invention shown in F lg. 3, 'I use a relatively short shell which may be'conveniently combined with outside. independent heating means, as an electric, gas. alcohol or other heater.

Various Ot-lYG-I DIOd lfiCQl-lOIIS in the form and construction -of my device may obviously be resorted to without departing from the spirit of my invention, if within the limits o-f the appended claims.

lVhat 1 therefore claim and desire to secure by Letters Patent is:

1. A heater for stretching annular pieces, comprising an upwardly tapering shell over which the pieces to be stretched are adapted to be slipped from above. and moved downwardly until stretched to the desired degree, a mount for a resistance un-i't exte'nding centrally of said shell from end to end thereof and tapered to substantially correspond to the taper of said shell and having adjacent its lateral edges rows of relatively staggered -upv\-'ar'c l-ly com' erging spaced threading holes, and a resistance wire coiled about itself in a plurality of closely laidtu-rns adapted to be threaded through and frictionally retained within said threading holes in a series of superposed turns of progressively decreasing diameter from the lower towards the upper end of the mount whereby to hea't the column of =a ir contained in the shell and to uniformly heat the shell throirg'hout its extent.

2. A heater for stretching annular 'p'ieces, comprising a tapered she'll over Which the pieces to be stretched are adapted to he slipped from o'ne end and moved ther'enlong until stretched to the desired degree, a mount for =a resistance unit extend-ing ce'ntrally of said shell from end to'end thereof and tapered to substantially correspond to the taper of said shell and having adjacent its lateral edges rows of relatiyelystaggered converging spaced threading holes, and a resistance 'wi're coiled upon itself in a plurality of closely laid turns adapted to be threaded through and 'fr-iction'ally retained within said lh'readi'rrg holes in -a series of superposed turns of progressively decreas ing diameter from one end towards the 0ppositc end of the mount whereby to uniformly heat the shell and the column of air contained therein throughout its extent, the free ends of said coiled wire when assembled upon said mount being stretchable \r-ithou't displacement of the main body portion of the wire retained within said threading holes.

3. A. heater for stretching annular pieces, comprising a tapered shell over \vhic h the pieces to be stretched are adapted to "he slipped from one end and moved therea'long until stretched to 'the desired degree, a mount for a resistance uriit extending centrally of said shell from end to end thereof and tapered to substantially correspond to the taper of said shell and having adjacent its lateral edges rows of relatively staggered converging spaced threading holes, and a resistance wire coiled upon itself in a plurality of closely laid turns adapted to be threaded through and 5 frictionallyf retained the column 'of air contained iin the'she'll and to uniformly heat 1 the shell throughout its extent.- '4. A heater mount for a zresistance unit extending contrally' qf said shellifrom end to end thereof and -',-having 1 adj acentits; .later'aledges Zrows oi /{relatively wstaggeqed -spaped ithreadmg llOlBSy and ayresistanoe-iwire adapted) to. :be

threaded'through and frictiorially retained.

witliil'ls'Sfilid-ithieadin g Zhfilb's dor heating the column of air contained in the shell and for uniformly heating the shell throughout its extent.

5. A heater for stretching annular pieces, comprising an upwardly tapering shell over which the pieces to be stretched are adapted to he slipped from above and moved downwardly until stretched to the desired degree, a mount for a resistance unit extending centrally of saidshell from end to end thereof and tapered to substantially correspond to the taper of said shell, and a resistance wire coiled upon itself in a plurality of closelylaid turns and extending across said mount in a series of superposed turns of progressively decreasing diameter from the lower towards the upper end of the mount for heating the column of air contained in the shell and for uniformly heating the shell throughout its extent.

6. A heater for stretching annular pieces, comprising a base and an upwardly tapering shell over which the pieces to be stretched are adapted to he slipped from above and moved downwardly until stretched to the desired degree, a mount for a resistance unit extending centrally of said shell from end to end thereof tapered to substantially correspond to the taper of said shell, and a resistance wire extending across said mount in a series of superposed turns of progressively decreasing diameter from the lower toward the upper end of the mount for heating the column of air con tained in the shell and for uniformly heating the shell throughout its extent.

7. A heater for stretching annular pieces, comprising a tapered shell over which the pieces to be stretched are adapted to be slipped from one end and moved therealong until stretched to the desired degree, a

'mount for a resistance unit extending longitudinally within said shell from end to end thereof, and a resistance wire extending across said mount in a series of superposed turns of progressively decreasing diameter from one end towards the opposite end of for-stretching annular pieces, comprising a "shell over whieh the pieces-to f be: stretched are adapted to -'be slipped, ta-

the mount for heating the column of air contain'ed the shell and for uniformly heat ing the shell tlIIQUghOUt itSEXtGIltJ 18: A heater for stretehing annular pieces eomprising' anupwardlystapering shell over which the pieces to be stretched are adapted to be slipped from above'and'progressively moved l downwardly u-ntil= stretched to the desired degree, and an upwardly tapering heating unit arranged centrallywithin said 315-. shell and corresponding substantially to: the taper thereof for wuniformly heating-the shell, thetopiof said.:shell being perforated-.- and constituting a supporting: surface rupon which pieeessftobeebentunayfibe laideforESO direct. 1' exposure; 5 to the rising i'columnij of heated} aiiw;i\"itl'1in .sthe::shll.

l *9.. .A heateri for @stretciiing annular pieces:

comprising a tapered shell over which the pieces to be stretched are adapted to be slipped from one end and progressively moved therealong until stretched to the desired degree, a tapered heatin unit within said shell and corresponding su stantially to th taper thereof for uniformly heating the shell throughout its extent.

10. A heater for stretching and forming pieces, comprising a shell open adjacent its top and bottom and over which the pieces to be stretched are adapted to he slipped from one end, and means for heating the rising column of air within said shell, the opening adjacent the upper end of the shell permitting dissipation of the heat generated by allowing the rising column of heated air to escape and said escaping column permitting pieces held within the influence thereof to be formed.

11. A heater for stretching and forming pieces, comprising a shell open adjacent its top and bottom and over which the pieces to be stretched are adapted to be slipped from one end, and means within said shell for heating the rising column of air within said shell, the opening adjacent the upper end of the shell permitting dissipation of the heat generated by allowing the rising column of heated air to escape and said escaping column permitting pieces held within the influence thereof to be formed.

12. In a heater of the class described, a shell and a heating unit therein, the top of said shell being perforated to permit escape of the rising column of heated air and said perforated top constituting a protecting surface for the heating unit.

13. A heater of the class described, comprising a shell and a resistance unit'therein, the winding of said unit being formed as a coiled wire and the free ends of said coiled wire when assembled upon said unit being stretchable without displacement of the main body portion of the wire.

14. In a heater of the class described, a tapering shell adapted to be internally heated throughout its extent,- the top of said shell being vented to permit the rising column of heated air within the shell to pass through said top and be available for bending and shaping parts held within said column.

15. In a heater of the class described, a shell adapted to be internally heated throughout its extent, and over which pieces to be stretched are adapted to be slipped from one end, the top of said shell being vented to permit the rising column of heatedair Within the shell to pass through said top and be available for bending and shaping parts held Within said column.

16. In a heater of the class described, a tapering shell adapted to be heated uniformly throughout its extent, the top of said shell being perforated to permit the rising column of heated air within the shell to pass through said perforated top and be available for bending and shaping parts held within said column.

17. A device of the class described, comprising a tapered shell defining an air chamber vented adjacent its upper end, a meansfor heating the air within said air chamber, said heating means and said vent causiug a rising column of heated air, which column is dissipated through said vent whereby to permit the shell to be quickly brought up to its point of constant temperature and to keep such point reasonably low.

In testimony whereof I afiix my signature.

EDWARD J. OVINGTON. 

